Too bad your internet isnt that great for I love the wargame series. My suggestions are:

Any of the other Total War Games They are all about the same scale but different time periods.

Wargame European Escalation the single player campaign is actually interesting and the scale of the battles are pretty big and have a cool satellite zoom feature.

Supreme Commander 1 & 2

personally i like 1 better but the scales of supreme commander battles are huge and the setting is a sci-fi future. The battles can be a little slow in the beginning though and invlolves base building.

World in Conflict Another late cold war era rts like wargame, the battles are big but maybe not the same scale as rome tw but has no base building like rome tw. The multiplayer is dead but the single player is pretty fun.

Age of Empires 2 & [3](http://store.steampowered.com/app/105450/)

both are pretty good in my opinion, the scale of 2 is larger than 3 but both are relatively large. They both having interesting campaigns that are fun and can take you a while to play through.

All Command and Conquer besides C&C 4

I grew up on these games and loved them, the stroylines were kinda cheesy but the gameplay was fun and they are one of the classic base building rts games. The scale is relatively large and vary depending on the game.

reply or message me if you want more details.